The commonest early problems seen in transplant patients include rejection or side effects of anti-rejection drugs. This is observed in about half of all subjects. These complications remain a source of concern throughout the post-transplant course. Minimization of anti-rejection medications to alleviate side-effects presents a dilemma because it is attended by rejection in up to about one third of all patients. Moreover, as long as anti-rejection medications are used, transplant patients continue to experience a lifelong risk of life-threatening infections and cancers.
These complications result from the interplay of several factors, such as infectious agent or virus, transplanted tissue, host immune system, and anti-rejection drugs. The net effect that is seen as a clinical manifestation is therefore the result of multiple biochemical or molecular pathways that can be affected by these factors alone or in combination, to varying degrees. Current technology to assess such factors operates linearly, measuring one or only a few at a time. Such technology does not take into account the complexity of immune interactions. Thus, there is a need for the ability to monitor such multiple interrelated events and to deliver integrated output for clinical decision making.